Summary The passenger and the pilot, who was also the owner of the aircraft and held an instructor rating and night flight endorsement, had planned a pre-dawn local flight. They made a night take-off around 0600 eastern daylight saving time (EDT)(1) from the unmarked runway at Sainte-Marie-Salom, Quebec. After the take-off, the pilot executed a right turn. The aircraft stalled at low altitude and crashed in a corn field. The two occupants sustained fatal injuries on ground impact. Ce rapport est galement disponible en franais. Other Factual Information The pilot was qualified in accordance with existing regulations and had accumulated 937 flying hours, including 253 hours in the Champion aircraft, registration C-GUHX. His most recent night flight in this aircraft was on 14 June 1994, four months before the accident. On 05 June 1994, he had also made a night flight in this aircraft from the Sainte-Marie-Salom aerodrome. He was very familiar with this aerodrome and the surrounding area. The Champion was certified, equipped, and maintained in accordance with existing regulations and approved procedures. The take-off weight of the aircraft was calculated at 110 pounds over the maximum allowable, and the centre of gravity was slightly beyond the aft limit. Excessive weight and an aft centre of gravity are conducive to stalling. The on-board instruments met the minimum regulatory requirement for night flying. The aircraft was not equipped with a horizon indicator, nor was one required. The propeller and spinner exhibited no signs of rotation or corn stains, indicating that the engine was producing little or no power and that the propeller was barely turning on impact. A complete examination of the engine of the Champion revealed no anomalies and no foreign matter in the fuel system. Following the impact, the fuel drained out through the broken fuel lines and no samples could be collected. Water or other contaminants could have caused the engine to stop abruptly. The manufacturer authorizes the use of automotive gasoline (MOGAS) in this aircraft. The pilot had topped up with this type of fuel the day before the accident. This fuel is more volatile than other aviation fuels (AVGAS) and more susceptible to carburettor icing, which would have caused a progressive loss of power. Examination of the airspeed and turn and bank indicators of the aircraft by the TSB Engineering Laboratory yielded no useable information. However, the tachometer indicated that rpm was close to zero at the time of the crash. Also, analysis of the crushed portions of the exhaust stacks adjacent to the cylinders indicated that they were at normal operating temperature at the time of impact. At 0600 EDT, there were no clouds; the temperature was minus one degree Celsius, the dew point was minus three degrees Celsius, and the winds were light. Nautical twilight, when the outline of objects on the ground is visible, was at 0605 EDT. It was daylight by 0640 EDT, and sunrise was at 0705 EDT. Conditions were conducive to the formation of frost and ice on surfaces and severe carburettor icing. The temperature fell until sunrise, then rose again, creating more severe frost and icing conditions at sunrise. The frost was light around 0600 EDT, and icing was present on the wings of another aircraft at 0800 EDT. Runway 21 used for the take-off is a dirt and sand road oriented 030/210 degrees magnetic. The runway measures 3,000 feet long by 15 feet wide and is not marked. There are trees about 50 feet in height along both sides of the runway over a distance of about 2,000 feet. The trees located between 30 and 50 degrees on the right side of the runway are considerably farther away, and pilots who use this runway on a regular basis always execute a right turn after take-off. The Champion crashed 800 feet to the right of the runway 21 centre line and 800 feet past the departure end. The aircraft exhibited all the signs of a low-altitude stall but no evidence of a spin. The first person to arrive at the accident site, around 0845 EDT, indicated there were none of the noises or cracking sounds normally associated with an engine cooling down, and no evidence of ice on the wings. There were no witnesses to the accident. However, a schedule of activities of the pilot and passenger established their arrival time at the aerodrome at 0540 EDT. As 15 to 20 minutes would be sufficient to prepare for take-off, the Champion would have taken off around 0600 EDT. The wreckage was discovered around 0830 EDT by another pilot during a take-off from the same runway. Based on the overflight times of the Search and Rescue satellites (SARSAT), it was established that the accident occurred between 0544 and 0718 EDT. Reading of the Montreal surveillance radar tapes (ASR 5), based on primary information, indicated that no air traffic movements originated and terminated within a five nautical mile (nm) radius of Sainte-Marie-Salom between 0540 and 0718 EDT. The take-off from the unmarked runway 21 and the initial climb were executed in a southwesterly direction toward unlit fields which offered little contrast with the sky and made the horizon hard to distinguish at night. Also, when the nose of the aircraft is pitched up to establish a climb attitude, the pilot loses his references with the ground ahead of him. To orient themselves in flight and determine their position in relation to the ground, pilots use their senses of sight, hearing, and touch, and their kinaesthetic (muscle-bone-joint) sense. In visual flight by day, the information needed to maintain control of the aircraft is provided by visual reference to the ground or horizon. In visual flight by night, pilots must also refer to the horizon, if it is visible, as well as outside lights. They must also refer to a few essential instruments to maintain the aircraft in the correct attitude. These instruments were on board the Champion. Without sufficient visual references, pilots can become disoriented and may not realize the actual position of the aircraft in relation to the ground. Disorientation is defined as the false perception and/or interpretation of aircraft attitude with regard to horizontal and gravitational references.